I am glad Vicky13 and Sparky are having fun with their GC, but be careful with buying GMC-200. If you loose power, all that good data is lost and your site will be as good as the EPA stations; Big gaps in the charts where the information should be that will be needed when an EMF or nuclear event happens. Remember Japan's power grid after 3-11-2011.This is the reason Netc.com quit selling GMC-200, the unit is good for the price, but does not log the data.

May I ask if you are considering setting your new station up as an outside or inside station? I have many but one of them is setup outside and on an air purifier for better detection rates. Even without the air purifier, you will more likely get the beta radiation detections if your station is outside vs. inside. The difference is like night and day.

Not to butt in or anything but my 200/Pi (purchased from netc) is inside around 2" from the floor. I like this setup as the inside reads are the most critical for me as the detector is in a place that I spend most of my time.

2" or less from the floor detects the max read for the room as particles (and gasses) accumulate and sink to the floor inside. The unit is by a west facing door so wind and traffic factors will be seen. Although the numbers are lower than a outside unit, this gives me (and you) the ability to see the actual environment in witch I live.

I also made sure to place it high enough to clean around it without touching the unit with the mop pad (wood floor underneath it). I don't even dust the unit itself to allow a natural accumulation of particles over time.

There are no shoes, coats or other articles that have been outside placed anywhere near it. Although you could set it up in a coat room or by the door where you remove your shoes, I find that on a west facing wall (preferably) by a door or window in a common living area suits me for the best indoor contamination check.

As close to the floor as possible (without touching it) is the best placement for this kind of indoor setup.

My GMC-200 has not been disturbed since it was deployed so these reads are historically as accurate as possible with this unit.

The fact that the counter has not been touched since it was connected gives me (and all of you) the most accurate reads of my indoor environment possible.

If you decide to do this (and you have the wireless Pi setup) you can simply use velcro or the 3m wall hanging tape and "stick it" to the wall under a outlet as close as possible (2" or less) to the floor.

Don't misunderstand, I think ALL setups are necessary to get the "big picture".

I simply want a undisturbed indoor reading over time without having to touch the counter or risk any exposures changing filters.

And DON'T forget (no matter what your choice is) to list the unit type and location details in the description for your site by going to the user control panel... Mine says "GMC-200 inside 2 from floor". You should keep it short and list any other details by creating a message with a subject like... "new station in Atlanta Ga." Without this critical information other viewers may not be able to interpret your readings correctly.

We are all here to help so if you have any questions, feel free to respond to this message...

Good luck.

Andersan wrote:

May I ask if you are considering setting your new station up as an outside or inside station? I have many but one of them is setup outside and on an air purifier for better detection rates. Even without the air purifier, you will more likely get the beta radiation detections if your station is outside vs. inside. The difference is like night and day.

I know this is an older post but one comment on the GMC-200 regarding if it looses power. I was concerned with that as well and the one thing I did was to attach it to one of my UPS's in my computer room. As a matter of fact it and the Pi are on a single small UPS running off a single 12 volt battery. Last time I tested it ran for over 6 hours with no issues. My cable modem and wireless router also have their own separate larger UPS that also runs for about 6 hours as well. It wont protect you from a major grid failure as Hay referenced above but for short term outages my setup works fine.

You can usually pick up used UPS's for cheap (sometimes free) on Craigslist and just replace the 12v battery. I got my last few from work for free as they were throwing them out as end of life components.

Just a thought....

Of course it is probably easier to just get the newer 300E or 320 and be done with it. I have the older 300 and it works fine as well. And all the UPS power in the world wont protect you against an ISP failure.

Just keep a rechargeable battery (9Volt) in the 200 and don't worry about any spikes.

The newer 300+ series have a problem with spikes after power loss but I've not seen any with the 200 so far. I think it's a flash memory thing on those units but there is no memory in a stock 200 so simple is sometimes better. Just gotta keep the pie running during an outage... No power means no internet access anyway so the Pi simply holds the data until the power is restored...

I thought my 200 had an issue with spikes due to power loss with the rechargeable battery in it so I removed it just after my station went on line a few years back. I tested back then and noticed an increase but it was not alarming to the point I seen on my station this year.

With the 200 and Pi on a UPS there is no need for the rechargeable battery anyway.

One of these days i will run a test to see how long my station will run on UPS alone, both for the counter/Pi and the Modem. I know it runs at least 6 hours, that was the longest outage i have seen around here since i had the station running on battery backups.

But regardless the simplest way to go is really a newer 300E or 320 and just understand the potential for spikes in your recorded readings.

The battery will not only help clean the power (so to speak) it assures there is no voltage loss to the tube in the event of power loss or "flicker". Helps to smooth out the power supply and provides backup power as well.

Gotta use NiCad...

UPS Stuff:Cool thing about your UPS is you can (with some creative thinking) make all the components run off a simple cigar lighter power converter so you won't need AC converters! You can wire em direct (almost) without too much trouble and get weeks of power off one UPS unit.

Yup I know where you are going with the UPS, been wanting to add a tap for 12V power so I can run off the 12v circuit directly and bypass the wasteful AC converter. I have a few spare UPS's sitting around needing batteries that I might wire up once I bite the bullet and get new batteries installed.

Looking at my setup I can probably go 12v for the modem/wireless router as well as the Pi and 200. Some of my spare UPS's are dual 12V setups so going that route I would have around 10-20Ah to play with. Going by the amp draw for the Pi and 200 that thing really could run for days on end with no AC. Not sure on the modem/router, will have to look up the amp draw on that to find out.

Ironically the ISP is the weak link in my setup as I suspect it is for most people. It goes down weekly sometimes, and is way more frequent then loss of power. I have a 4G Mi-Fi setup I could use in a pinch but that belongs to work and would require me to access the Pi's GUI to switch over.

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